Most suitable salt which can be used for efficient clotting of blood will be :

Solution

Chemistry ma’am · 3 steps

Blood is a negative sol, so the salt with the most highly charged cation clots it best.

1. Nature of blood. Blood is a colloidal sol whose particles carry a negative charge. To clot it, you must neutralise that charge so the particles come together.
2. Hardy–Schulze rule. The ion that coagulates a sol is the one with charge opposite to the sol, here the cation. The higher the charge on that cation, the greater its coagulating power.

   Salt	Cation	Charge on cation
   Mg(HCO₃)₂	Mg²⁺	+2
   NaHCO₃	Na⁺	+1
   FeCl₃	Fe³⁺	+3
   FeSO₄	Fe²⁺	+2

3. So. Fe³⁺ has the highest charge, so FeCl₃ neutralises the negative blood particles most effectively. That is why FeCl₃ is used to stop bleeding from a small cut. The answer is (c).

The idea to keep. For coagulation, first find the sol's charge, then look only at the oppositely charged ion. The higher its charge, the stronger it coagulates.

Answer from the NTA final answer key. Solution by PrepWiser.